Conventional navigation systems for vehicles, in particular motor vehicles, and methods for operating such navigation systems, already exist. They serve to determine the present geographic position of the vehicle, to calculate the most favorable route of travel as a function of a definable destination that is to be reached, and give the driver instructions as to the route of travel.
These conventional navigation systems require information that is necessary for determining the present location of the vehicle and calculating the route of travel. This information includes, for example, road layouts, turning conditions, etc. This data is made available in the form of a database. For this purpose the database encompasses, for example, a so-called digital map that contains way points and/or decision points for the possible routes. The database may be maintained in vehicle-installed mass storage by conventional means such as, for example, a CD-ROM.
Also necessary is a positioning system that identifies the present geographic position of the vehicle. The satellite-based Global Positioning System (GPS) may, for example, serve this purpose.
An electronic data processing device processes the position data furnished by the positioning system along with the data stored in the digital road map and determines the present position of the vehicle. Destination guidance information corresponding to the selected destination may then be provided, visually and/or acoustically, to the driver by the electronic data processing device, based on way points and/or decision points on a selected optimum route of travel.
Conventional navigation systems for vehicles are substantially made up of individual components having different functions. At the beginning of a trip, the driver first enters his or her desired destination into the navigation system via an input unit. A route list is then generated by a route calculation module using a database. This list is used by the destination guidance system, in combination with the vehicle position, to generate driving instructions to the driver, which are output in the form of graphical instructions or in natural speech.
The interaction of the individual components is permanently defined in this context. For example, once the route list has been calculated, it is modified only if the driver so wishes or if the destination guidance system detects that the previously calculated route has been departed from.
The type of output is also permanently defined. A user cannot, for example, replace the symbolic images that are normally available with his or her own symbols, or add additional information to them.
It is moreover difficult to incorporate additional functionality into the system. There exist, for example, travel guides on data media, usually on CDs, which can be used instead of the data medium for the otherwise usual digital map, and which contain not only the minimum requisite data but also additional information, for example regarding places of interest. This information can then be retrieved via the navigation device. This information retrieval is accomplished, however, via the interface defined by the navigation device, so that the configuration options for the human-machine interface is limited. Since the otherwise usual digital map is moreover replaced by the travel guide, it must also contain all the data relevant for navigation. The production of such travel guides is thus difficult, and there are only a few suppliers. Local travel guides whose subject matter is, for example, only a single city are practically never created.
A further deficit exists in the area of georeferencing. For example, it would be desirable if a destination, e.g. a parking garage, is made available in electronic form in an “approach description” that could be played back on the navigation device. It would thereby be possible to reach destinations that are not contained, or not correctly contained, in the map. For example, one could reach destinations located on streets for which no house number information is available, or entrances to buildings that are not recorded (parking garage entrances, hotel lobbies, etc.). Extensions for georeferencing based on the transmission of data do exist at present, but because of the varying map formats of different suppliers, they are difficult to implement.